[dem,lat,long]=readSRTM('TUNGURAHUA',4,4);

figure(1)
axis equal
v = [2300 2350 2400 2450 2500]
cs = contour(long,lat,dem,v); clabel(cs)
hold on
plot(-78.48889,-1.43382,'r*')
text(-78.48889,-1.43382,'  TBUG')
plot(-78.48844,-1.43427,'r*')
text(-78.48844,-1.43427,'  TLEF')
plot(-78.48664,-1.43430,'r*')
text(-78.48664,-1.43430,'  TREX')
plot(-78.48748,-1.43515,'r*')
text(-78.48748,-1.43515,'  TMAR')
plot(-78.48759,-1.43428,'r*')
text(-78.48759,-1.43428,'  TBAG')
plot(-78.48765,-1.43337,'r*')
text(-78.48765,-1.43337,'  TGRS')
plot(-78.48743,-1.43264,'r*')
text(-78.48743,-1.43264,'  TLAV')
ylabel('Latitude')
xlabel('Longitude')